There are eight official planets (sorry, Pluto) in our solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and ...

Simulations suggest Pluto and its largest moon may have gently stuck together for a few hours before Charon settled into a ...

Pluto and Charon are in a region of the outer solar system beyond Neptune called the Kuiper belt, which makes them both rocky ...

A few decades ago, the Solar System had nine planets, but in 2006 the International Astronomical Union reclassified Pluto as ...

Since New Horizons' close encounter with Pluto 10 years ago, experts have come to think of the dwarf planet as much more ...

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In 1928, the amateur astronomer was offered a job at Lowell Observatory in Arizona, where he discovered Pluto. In 1934 ... the mysterious Planet X. Not long after its discovery in 1781, the ...

A powerful new tool comes online this year that could help astronomers locate the mysterious planet hiding somewhere beyond ...

A new study suggests that the origin of Pluto's largest moon was quite different than our own. Here's what you need to know.

(CNN) — For decades, astronomers have tried to determine how Pluto acquired its unusually large moon Charon, which is about half the size of the dwarf planet. Now, new research suggests that Pluto and ...

Previously, scientists believed that Pluto and Charon formed from a massive collision, similar to the Giant Impact Hypothesis. According to this theory, a Mars-sized planet named Theia collided ...